In vitro comparative dissolution assessment of different brands of co-amoxiclav tablets in Pakistan

Abstract

Dissolution test results are the principal indicator in estimating the in-vivo bioavailability of most oral solid dosage forms and are an important quality attribute to assess the generic formulation. This study was designed to assess the release of co-amoxiclav from finished pharmaceutical solid dosage formulations. Both innovator and generic tablets of co-amoxiclav were subjected to dissolution testing (USP method 2 and HPLC). The innovator’s product (product A) met compendial criteria regarding bioavailability of both amoxicillin and clavulanic acid. The two generic brands, product B and C, failed to meet the criteria for release of amoxicillin (i.e., 80–85%); however, they did achieve 100% release of clavulanic acid in the initial half hour. Moreover, analysis showed significant variance between the innovator’s and generic brands (p < 0.05 for both of amoxicillin products). Hence, the innovator’s and generic brands are not bioequivalent for amoxicillin release, despite both compliance with limits for clavulanic acid release. Failure to achieve dissolution standards argues that compliance with compendial guidelines is critical for generic manufacturing of co-amoxiclav.